SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fa0b4efb3a2b9fc5d74e9f4d1da6b5856ef3d950f053a4fa8bdaa1623423a44' 
  AND token = 'S8xOYxOuY+R8O0KrWTU6NBKE8becBzYR1KuBq8SNIzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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