SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df4fb02fa689b2a5fb79686407d0b9426b92ce45f53f89a2cd44217a3ef66600' 
  AND token = 'pWR1RKMZth6ziycWYH/YVOono/ufppcUDBYmfgJo36A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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