SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fb1f6132599a31aa22bdb0f30caf04330a66aa54b37cbf0f4333defa6b58988' 
  AND token = '86AIMaou5GLocw9jdDfH3yaXntyMJH+QxKPfedOodUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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