SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1af8663e434548bb07f7fdd3296e68de74b44ed81e3eb67ff8cbd6cd12730c26' 
  AND token = '69MLV198NmkRFEowmJXazY1lDga5jUfav7Ja3STk0xw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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