SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f5dca5eb806b3f4f1980095f946c03441ad9bf5f81fca7fb1b4e6b750a6fbef' 
  AND token = 'lMJimyh6N3t56+LkfSkV0W6tILYTje999YaoMP9CpNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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