SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b43b2e6f95319798bd9c2b8cd361dc90087afb454a94670e26386d53a2853e5' 
  AND token = 'h2KTBSuxVun8RURYE6JJm0P0FdMvB6cnejNmIgIwSXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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