SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '424146f37e14f7e9ae6c5aed268d89a24e9c858062d5241da50951aaebb2a15d' 
  AND token = 'M/i69/qCMuvtuhCFYZhbI8Lj/5bPMGXvWCJD3gVMaFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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