SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f636e68e09e2f6b03e3f2810d017742fc03eedda936d691d7ffc2104188ab7e7' 
  AND token = 'KCwNY7kb/aznZaZiwhK01yU3tPfmvcdwHgn/k0xRtQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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