SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '944c33b52429a4fb72dea76f350bcac4bf4c2cc6115136cf8817822f521276cd' 
  AND token = 'vgej7klnE69Cj5NMskHtKsOw57WUU7opghnSjXJdO5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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