SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1af071e4e6b4f6cf433d4afa44cc7b0b688cd2928c7fb46f2fab93bb271a607a' 
  AND token = 'CgggbdGb1IwTpmUESTrSQ4Bi2KZzJSvlJdzjejg1DNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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