SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '082f9e16bbc6c65bc29388b4d4a257c46b014eb66e043d16863f7d6a85e721f2' 
  AND token = '15HLsf48wwZMhdaAnEWlooFjK54pBKLJcAygFKY7Rps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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