SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c1e0075e3cc09c59dba213baf9d1b719f406eb68b645721226537b432f654c8' 
  AND token = 'A5k1JoVJ4GT8xojE+g2ZeTKGJdpKvvmXzlA6mPxuTDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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