SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87d2695a64f047817b8ae31210060beae4d23fcb0ae5b0afb37f637b6424e566' 
  AND token = 'O0pQveA3msWGpspOrgtZi4zapWwiJ0gzWlvY63Tc2k8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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