SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2361aee13f661114b252149cb1da63962938448cf97cfd0669cdcc8107b74caa' 
  AND token = 'Wx/RBX5LUINxv4BRS2x3UeGzOsXiLNrzDYeiniv4dLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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