SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '40a0dad91085e504add84a49c22ed2a86f0e70dd3079709ebedc431d67af7a5c' 
  AND token = 'b1/1SknYI/tZz62BTSpj5KIrQhMQ1NoDjlvNNHPAJV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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