SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '21024e7941f914ea592f6e90a131a25e3cfdc204f543f9c66f33fba416fdc2bb' 
  AND token = 'uPmqxoTH2001p3rQlzdlfXfHSDy84dM3mCVzMuMhCnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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