SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5198bc2a29738059701c16ddd46f8b8e921f05236ce0c87227a2cfd8772c0e51' 
  AND token = 'ydbUQxb2GH1MJDCQjN/VypCQmKIujU4ZLZJXAo61T3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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