SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'edb59ceb52e5c628908a337795a0e503562d4818a1c9adfab5ed96e97da31fca' 
  AND token = 'ZNS8sfAvi/4qzC1eSauKdUBHsDuar/P9Xy2SwWPfxGc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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