SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89109bdcf4bd7267724816307a243eccef8f50cfde031d1ce06109f23e20c615' 
  AND token = 'zawitdv8ulqxIQRIKmUmWWIzb8zPitSN7aZP1kCmoUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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