SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6414dfbf56441403db309ce52d83fd8d360f35273266d1db38c0c3cddd337754' 
  AND token = 'fV0ab5Xgz5v8frqNTxhkfFdX295Iq0v303BihQcSqR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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