SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bc1a264b17baef9e84d6f6a1562fa3a72ba180cb3125f112e198c44d85ea959' 
  AND token = '3pKBWolvhb9z0/DoHPN3YwKjOFyxzVxSjtUHxNqVsqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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