SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66877b7c115bd1ae28db9cd3417f8a7bd8d42e649fce352e969143a6e650c6ec' 
  AND token = '1aG6KRXrygIecW0SE/OpJq3gDb9aeHAarRhieu8cv1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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