SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f4d09d87c09db3e87ecb12339e26be82b31161035de2bcb4ffe9821e237f8f2' 
  AND token = 'pKa+kJREWEoCDO00MSI+bw27EVFLRt1jQaMUDAScEKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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