SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc8a7307bfa0119feeeefc1597d674611d1bba8af1f7dc2a2bbb0a2ee16618b5' 
  AND token = 'AFjbALuUzU2T65P2C3ebawXr/jIO5TFBdhezEIv3vwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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