SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f05810bf70228e2d68f6a87b42fe8ee85b8f3a83da45c6e3a2344a4e7c6195d1' 
  AND token = 'e49CEpFXHLqNKNz0kOP60KwNfpI2Mhy9Y5VclRqfk9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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