SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80cf227cce29bfc559968769ac566ad7a39ecfb5daca58f163cd7b2296566630' 
  AND token = 'U153reQgiFSgtku+lk9fk+1MwliOqHzdpx0uLFGp6zA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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