SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66a2cb34051b4b0e13932d095165fcedccdeffe1670b2efb411994cc3e53309b' 
  AND token = 'kRQFCYM6rzZbxpRDhJXFnbF8mdV6ZUnsI6Ye66VmYc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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