SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4f5f3341b22f6c1cad79580ba9b2cb52b82cc15ebf737f907bc2647d64e80e5' 
  AND token = 'uZ/K2PIbHoFs6Vv4jIRDY+dAYciJ6RJqChmf7SPVhAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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