SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fda10d22fdd155b10c07b907d81675672f29deccc24f7a1b459fa74cd48113b3' 
  AND token = 'lUrHsyaj7goBQXlZRvt25jNz8w68QtLq5GRZ7u5sjpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}