SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66e894be28113346e9ff60a75c4263e39c67e7ca8779db9e28358f98d32a908b' 
  AND token = 'hYb+gfTm0tZNffuQRXVgGhSKIFlZ3z78wEjfZIfw1TE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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