SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '356f277531e61ba03b0f858338d16620cbc3ba4d0a39968c2a4157fdad087de9' 
  AND token = 'Y866uTMUlRq3RhfSgjZZ7KUVTwMPhKDDP2qaJcacHM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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