SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf3a9685d9a236a0ad22fbaba6f8eb5683841c2124743fb4ba058f488b46589a' 
  AND token = 'h22q2lTQfSznrJprzWaDcrYQLMRyEsLarP1l3zaJXAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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