SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c750cb7557eca72ec3c49f90e3f66921fb7903fb965c31f452d21a29fa8ff07' 
  AND token = 'XHG4SWQSiKrg0+d+uTAnH4lV/SUHDCYB3vkrw9dIKYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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