SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f04f0c5f3324f0c8522541a9af90734c54080d3dee607b321920e29136bc587a' 
  AND token = 'y6ufg7fqJDxaRnNY3wUJ1JW6SREjJYZq4SlzapG9BVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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