SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b463d646eaf95c86f12c11205a73adb91618f045e39d188745a63152b380bb1c' 
  AND token = 'BTPsU087j8cJUtEiiYrxjhIw0QF9GM4/Ymk094oHC8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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