SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab15b441f2b501daf3a95dbdaf8a28f8f751a26e236bdf10a8acab994e6aeff1' 
  AND token = 'BwZfniaVFdCGTcfmB2+Gm7jKR1Fzzve3Yvzhk9o6LVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00087

JSON explain

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