SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54faec9d9374442ff6f7ebbd8c21579be4d6abcf15f8b345527398f62101b369' 
  AND token = 'DYy/XKnTOIqFFlU/SspjjZMuXjYuDNZ+mD7nfTf5Mc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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