SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d3ed0a7d1e48f8ac8ab6d2eb47e25821f513d54b2c3e63064f7447bd903658d' 
  AND token = 'ThGRHnyQYNsRZhVkZiXowEvlTqoujZZKNkQFIJgatXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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