SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '926abff1e0ef8c5d29bfe512843e1756ca335355594b0f05267d1af0fed15dc5' 
  AND token = 'uEJmPaKKjWgdYNX5Tno+LfXhr51sSBOIH36HqAYfCSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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