SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0261ba4010f118dedf9f23d0a4f7534dd89bbe3ba282a6f5ee0c776b37bec5c6' 
  AND token = '4EBUymOJqN9WdAl0XiLi0oJI/CH3yDw3E1vJZduJuos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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