SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23e564b42b1333749bc404305d37e18ab947b1ceac4b0c71916da0fca1319f48' 
  AND token = 'xatwAu1fADuOYAe5OnSKcZ5ZPA3ZbiJqInaPgvednKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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