SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c18b832d858c85f969966dbe17a2042e6c2167c6f6f053e874346f34a8b2248' 
  AND token = 'pJHzl0/s6gerkgWxvxB4NZooifwBONLPXvgALOHhDVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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