SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c6f6658ecc31d5438a311fff25a4f208742266b467d5ba3d7c7bbea371027ba' 
  AND token = 'PoZIVSeTTRrrd/Y2B4Hbshk/CsVqHeQNgTBdHl1wzwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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