SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c3c0c12807019016baf3e52d0d867a04a7b187ba5feeb8e33ed7833cac2ca2e9' 
  AND token = '83H2CLYc/wgYP4jgnVH+VhY6OFvn+XGq0FZWm+RMKfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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