SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23e1f9ff444eeee8deb63e632838b7ce76335552b32d0e15b9694792172c305e' 
  AND token = 'AcOAEy7PdMMArpodmu6PyuXVQQMG0zLhlUKnoR5h8Bc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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