SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fa565ba4ec8c7806d87fcf03da19ad407d6a6fc89c5a2ec8f2cf506d6438591' 
  AND token = 'Y3ytasJ94+zt2HNMZFm0ELQkXsqdcENbTm3Pemvejoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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