SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd89d03fa26ecbad1a2790e5d950348dbc33e01181aa250d8494aa9971fb4894d' 
  AND token = 'cYMD8zvqLAiRCJsPRyhJwBlITJHu5jQBnk9hHHQ/xJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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