SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26a5be19a7a364c33d918d155bc756b754f1a12c79a6e5f46d4044c6a9cf0e05' 
  AND token = '87FBPg69RIo9IS1+HFPBGxe+XtYh6lDvx6najLlLpJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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