SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b993fbd00c465029ab28a918a1f69a29cddd8cb9644c2813233ac43196ea65d' 
  AND token = 'MQM+vNqDnPIKGzZjV0Gj6292k90Yb7WD+Onn1JwjuXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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