SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '388c956a2d6b2ecdc101d654d631e54a9c5109b69b4523969f2882e872d2bad5' 
  AND token = 'iJezb/S6OJqtVr4bKENnol29yaN+xIpWkxKFTwoxD0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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