SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98896e7a06c484bb6a31f0fce4bea830723d54574c8f1931546ae1b6feecec9b' 
  AND token = '/++yQ2GqZuS3YK7t8yBilCavnBs4H2z8ElnNO2Yz5QM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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