SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08fc3496e1008951dae21b1967e4bba0f8bbb20d6bc575d35c3775425a5e13fa' 
  AND token = 'kuyHV5qHr9a1rWwzmHAwewQDvE6k0oC7nyWgOIYpUrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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