SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc5dae0aa9a2f9b1ec2fcaada111a85026a87c0197f095f515b508248c9b5ede' 
  AND token = 'hN/WU5F3Vl/j9e7y4dQe7jnKqWCmP5SW7mveKzgZ7HE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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