SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcc9e0a83aa5d6396a0721ce19e7d8eafa8172da9bb841149cca6959b12686c9' 
  AND token = 'iPkHifAkYw9djK+1L0GoEkXICWyr04pdPTdmIGXqMbc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00069

JSON explain

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