SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '717355b998ee94861f31b1499a997839c4da91ce9956b29590d62cb5e06f57ed' 
  AND token = 'dm5RLjzn17hfHKl7VdqNzusm2pBnI5MgmI8Zcv2hq2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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