SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '190f6e9bd87f9b770107dc7af09e80bdcce13f0626a5538f0b1ab628b9b444ad' 
  AND token = '0xiMYQI/dur3sf0HqEJ+3vWtlmvDiGBngApRfoV85pY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}