SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c5bbb36b627fc191190a2be8706a6f652f95df577b4b3acf94e4ef7c1b99239' 
  AND token = 'gq18/dBP5gKDXyCxURAeLrik7P7LusxMY/ikxTZ0MuU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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