SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84e621677fd7abd570e5e2ee4e1e6e104796ae5ca558bea1f926bcd64dbe1062' 
  AND token = 'OoJb1MtkRBMF/zSaK+JmuvX0oR7ohjclaN7fN349/FU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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