SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f604c03fcd494a397dceff6094240f8fb69f4371ea3abfdbafe01f9365a79107' 
  AND token = '16T7Yoeo87IUu5KngjOoOqUHcfgIhMV0BQFTdUrnp7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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