SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f491b313ebaeed4fb4d79992591a733ca3611554041610e92773a4931b989973' 
  AND token = '4if4uy5WtNKol9cCfAGHNydbpbb0NC1O/FSMOTLl7XA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}