SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08c1a47a8ccde4f5f93f6d91e85a1a991311a7b97bc82d2c361e33363be2911b' 
  AND token = 'pCoI5pultKznKTxZYEG+QfbtcomKCd/ffb4d5kzMACw=' 
  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"
    }
  }
}