SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd52130cce03289979cec043c6851269b1f3e8ccba2b2d176f36edf6507dffe7d' 
  AND token = 'ecQLzDWpN4IXcq8vSpxnobVMOqjU7rErM0cDEzW+1YY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}