SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57cd1af53533aeaaff31c87f586414eb136b369468f935a0918aad70bdd7808e' 
  AND token = 'svB6bdw8Oboi9UM6ZHguTVelX6Oaqgz2V3ENxUL7QbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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