SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '490c5c8f8c8a3285cc54b65085614f7f55092fe7621dd4a919cd8f10957f19e5' 
  AND token = 'cEQP/VFdtY2P66aLGSFd+hTv1iTulz8pc1xQG5SIJXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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