SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2887cb676033126046a0863a62762438b95141d82a79b9ceb1a24753d70ec67' 
  AND token = 'EKhf90bA7IeWw+94RvgfdJjNLT7xbVDvoXQqcXGzVN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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