SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb6530220851b1d42b80732997ed484f9a591a26e6be1e5ac7d184f7ecbeb2b3' 
  AND token = 'UuLfD724GLycREbSofZUinti9ybU6LJgCGOitW1QLys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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