SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bd34fbe25211e902d17cef971e1111b871669b9d26adfc125f3c85dca48106b' 
  AND token = 'ZtZp3LX9R9vHvxutyWLjJQ/vGUisyARIgMRu4g6QmA4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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