SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c151765cb8b3948dc795eec18fd642707fa5b34c97b24a1ad55416e67f5f3ae' 
  AND token = 'KG4TBYxuyGQgIMHfk3W7NMdK5k7rX3R0bF7WwjSRImo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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