SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3adb3a44030ea63fac9285e2fe04c745b82710a320097f430a30d2359c0b6807' 
  AND token = 'LwlVkEZql/oJN/OnvuKAzMVTc66CoCisJCwKjpwz1to=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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