SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a07fb41dd9c06566fe721d5df2eb2ef6cf75962d6cef6e1d3f48483893878f0' 
  AND token = 'qElOrZgbqbv3QsEqLM+7riea258RLSePR5pWUTSXMjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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