SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61536024197e091bc1d832c0bd33f991fd1a82ef4577060df32ad63ad39e66ac' 
  AND token = 'cwucmSTnEOntuncsUW2l0UbcMFrrty6GAHwuBitRZjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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