SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1eb1c8b32aef4574e9997898ff6cb9ec0de847a250c4f7364b83153b377dd61' 
  AND token = 'SYeLUnNCwMYdncqK96cgS0tVl+3sVbAWqjhE/DnGJ/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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