SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e861825a117db8e3311a14bc64fd2fc8823f1751c9d4965ab50c28d2415ab90' 
  AND token = 'kJ9BK2ApXNQyOc2fgDdBQWwnieE1QP58I9FKpJHIfZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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