SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27f6d0e0cdf40b612ef36a157248c29cefc58fc5150537226ffbdb374c74e33f' 
  AND token = 'Nw40putV/UF9c+AxQy25jlxIRlhGA7fNNa+VPKZH2lM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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