SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2905c3673db170c454bcea8c167d07c24510084ad1cfea6502552deda29fce96' 
  AND token = 'N9CE8qfF4R6jnNBCRPvlNgUZoyEpkQHB3GQa7+HuDbc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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