SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db7515ae5493037da8ef878186ce75232cf950deb48c437a236fb1839ebb7339' 
  AND token = 'geq0+6TMnGFxDxqjAQbnzWSMFKvgCPLi++6wlMG1/iw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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