SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e20dd14351455151991fd7a8c366d4ec226c7724134127789ba396f00f98ddb' 
  AND token = 'kimAe+Rw2hsQetNSxaYDTnBXom6KzDnVR/Ns03oaMcs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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