SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6983ed67cd21908e929bc2aba6541041a767b535f51021be4ad9f6e72ba481b1' 
  AND token = '0Wnc/+5MB05UHo07vlWqWr6WenYKoIvUgS3Gr5RV+Vw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}