SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2d95628a1c166f0a6dd8fa1715bccb6a6afd0f3b9b06bb9d4fdb7a254ebf6da' 
  AND token = 'InBhnvmGLOBl63TtlRg5I8qmzBk4vdwQwc5H4F6EV4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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