SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '279f3f9b64933db2f413c16d26708d30c4e55e6937a56d60677b1bcb7b710378' 
  AND token = 'ADZXJcRKXfaLrOWwgl93Hg5BFKAuJPAX88SQh+5CiZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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