SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75aedd955c379b8ef04b55f3de842f32ee0c24c43d68b10625605fe89b360f8e' 
  AND token = 'arVTjqH89Z7Cq4KspnIBu4aWxvwujN+9PH0d+BCLfMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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