SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '995aeb91ec0b364f67edd15cf7962836e8530301ed1b69273f806f683ba0e089' 
  AND token = 'dKg3VoDnePeFxgVrl59PXPs/z0mEOz1n4vvoVHvIabs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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