SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3734edaaf24994418d8f212c41476f8ab55d796f0186179fb2e11234ef6bb31a' 
  AND token = '5rUShy/mM1b3907se9LGhlpCwc4mqns1SOqPTXzviFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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