SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65b2f6f26c9059ec899bb060b7074e51c3d4d6a5a5045cef60f66b9335d83480' 
  AND token = 'rCw8x9j+UTPzqnmLtYUA8Dwh0nGaYLnCUp+lvKjQcyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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