SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4b1db7da1de73132a2491de4d4bbe5165eef7a1d43502ca5f4ae481d4031b5b' 
  AND token = 'l2pGbCwXgNe2fOrAanFC5scbeNNpnQA1yPuSOK3zmo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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