SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa6d13850dab6248134363c145217a23c6f677b3e3525da72682055d6d88f96f' 
  AND token = 'vgwNvN/xGDQBlj3MrgSZVS4/5k41zWOfDuJu7BrdaDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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