SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a7bd3591749b2d37d8d9a19a14e9bdad73f9f34a97266a961f9042957c84fe4' 
  AND token = 'TTw75hCRKQ/mt/pcO3OIJ4omEkBRLRYlao/VmHQiq5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}