SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6394560289d66751af9a011c1086363a7e598e8ecb4bc70a55c2e2cbe62292ef' 
  AND token = 'kwockq11BjOh4rNwfmFhgPzJbmzIiHlRo7C4XSq4BYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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