SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e1f698519f19e366fa81198ee2558c2f6b71d4b7a7f6c0916e684f7feafe7c4' 
  AND token = 'oSJ009/NCq+YTphHGf304+DQ0SyCKnO/Alfk1+5XE5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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