SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '888dbdd4c004f5c5745b05cd2035d25aa9765ac22952a17e23815f99c2104cdd' 
  AND token = 'kqBjKouxBrFO2UDgvtfVtP+AKsqaxGBQUxjK9gSu8/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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