SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f27994a5e6b7bc9d61e546382aae9c6d4d227c63375efedbacdf0d5cf674518' 
  AND token = 'ZK+1c4qlHkBV+ioBmllko+Ox7YOjybNg0z4cwgzbQKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00076

JSON explain

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