SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd94cb18625a6fa07aa571c4efe6336ea248faa1f74f991fbe85bf240e69c0a03' 
  AND token = 'cP6gRdbQf5mPrZlXmMpPKQ34n+IqZsox/Bxv9o2x020=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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