SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f0fb116ac3e84542094a62b3413084727d5fa1fb13da86763594fd52738af9f' 
  AND token = 'ajrLxYFU6CcuCw3cGqxQiEMbsMhTvpcEzwZPfkM4LK8=' 
  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"
    }
  }
}