SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '110fb55d42a28046c614041619e878ed21d9024665cd2c35f3aff15df50de0fc' 
  AND token = 'iNS4Qj49gNweRSybTZYe+1iwo4+kGDKokVRazNrCOHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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