SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4dac30326a3cb01ea42bb847991f969ad9d97f2eb248fe117f3d2d9129f12729' 
  AND token = 'vUrKfB8T/y9jyTZJU0d4uEMv+7UGdBFSGRuMn0/42P8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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