SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a6a6b658f9558f41cfcfb860ce159c080a626a83f6c62ee5af3d5639a3227c9' 
  AND token = 'EBVBIWw9QOq+FOU4jXF2izggivG7BZyG6bajj8NhCxI=' 
  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"
    }
  }
}