SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a666c784b651b361c1db4b3649fa9f92515552f2299df115329dd9f21a7045e' 
  AND token = 'Y+IFGyltnGO7I0cVMqLuQFOxG9/xZdKbubwAyhnY1OQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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