SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e93d49c162570bcb4d4c64a6738fef5a31ebb47fc03c296ffae10cd23494c1fa' 
  AND token = 'bTlSQP5l10nGLFlPtqwtnizM/acHBKhe8kPHr6pyl7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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