SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c41750d56b027a256ad6278bc303dc109bf23b73cb6502c35c44304d945bb28d' 
  AND token = 'ofqMILKJlVbUZBuxYE7G+eYet9MUkPiQyA+fzHUyd84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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