SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77eec905c91e533a2f860595373557c78386ef43a9e4664ec252195fc3c261ef' 
  AND token = '38mCq2pHFOnbASFfE4tzW7Gqo26/wbhy1NJvdrTgnKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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