SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a72afcb8719604705581766d2a12a3efff8dd825f4fb4a785f341203088d9edf' 
  AND token = 'MSjNXhOjPnrhCFHGJ/TdxWKDy98TZZ15eRCnbsp3JSQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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