SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b48f8b3117553a57d2c352d6f5975a3875819780de2dac76faa9dd79794fa384' 
  AND token = 'UMlVrkihaP2/tWBowqzjCBFepf8NKnlMvzKnE2StVNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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