SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ccc6f33d5bb98c2037114556e6862a2a7fd613d3c1be1d123d461afd7c486bd' 
  AND token = 'wJ9iuGV3hjeVFTcfohVUKtMmR/6rGK5drCGWrFdI2BA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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